Basic knowledge of network application

What is HTML?

HTML (Hyper Text mark-up Language), the Hypertext Markup Language, is the description language of WWW, presented by Tim Berners-lee. The purpose of designing an HTML language is to be able to easily link text or graphics stored in one computer to text or graphics on another computer, to form an organic whole, without having to consider whether the specific information is on the current computer or on other computers on the network. This way, if you use the mouse to click an icon in a document, the Internet immediately goes to the content associated with the icon, which may be stored on another computer on the network.

HTML text is a descriptive text consisting of HTML commands that can describe text, graphics, animations, sounds, tables, links, and so on. The structure of the HTML consists of the head, the body, and the two parts. The head describes the information required by the browser, and the body contains the specific content to be described.

What does the Internet do?

In today's world, the Computer Information network enables people to exchange all kinds of information at home and even around the world, which is called "to know the world". In the current global Computer Information network, the most successful and the largest coverage, the most abundant information resources of the Internet. The internet is thought to be the embryonic form of the future global information superhighway.

e-mail functions on Internet networks that can receive and send e-mail messages that can be a letter, a page of content paper, a business card, or data and software programs.

Using Telnet and FTP functions on Internet networks, you can also directly use software systems for remote computer hosts, as well as rich information resources. For scientific research topics, papers, library books and various scientific journals and other image text materials, can use WAIS, Archie, Veronica, Jughead and other tools, according to query key words, query and retrieve them. Using Gopher interactive search tools, WWW Wan hypermedia information access tools, Netscape Navigator, Internet Explorer, Mosaic, I-comm, Lynx and other resource browsing tools, can be more convenient, More vivid access to and browsing of information resources.

Through the Usenet news Group on internet networks, we can also see the world's public sentiment, global weather forecasts, world major sporting events, news reports and various advertising.

The talk and IRC features of Internet networks provide us with the opportunity to talk to friends who live on the other side of the globe at any time. In the United States, the use of Internet networks for simultaneous sound and image transmission is a harbinger of the possibility of an electronic conference.

With the help of multimedia technology, internet users can watch and listen to animation, image materials and audio data from all over the world on the Internet.

The Internet, China's authoritative institutions translated it into the "Internet", some people call it "international Network", "Interactive Network", others call it "Internet", "Network network."

The internet is not an e-mail, www or browser, it represents the development of the global information industry, its standard is the network Esperanto.

What is TCP/IP?

TCP/IP (Transmission Control Protocol/Inter-network protocol) is a network communication protocol, which regulates all communication devices on the network, especially between one host and another host, and how to transmit the data. TCP/IP is the basic protocol for the Internet and is a standard way to package and address computer data. In data transmission, it can be visually understood as having two envelopes, TCP and IP are like envelopes, the information to be passed is divided into segments, each paragraph is jammed into a TCP envelope, and the message is recorded with the section number on the cover of the letter, then the TCP envelope is plugged into the IP big envelope and sent to the Internet. At the receiving end, a TCP package collects envelopes, extracts data, restores them in the order in which they were sent, and verifies them, and if errors are found, TCP will request a resend. Therefore, TCP/IP can transmit data almost without error in the Internet.

For Internet users, there is no need to understand the entire structure of the network protocol, only to understand the IP address format, you can communicate with all over the world.

What is an IP address?

To enable many computer hosts connected to the Internet to recognize each other as they communicate, each host on the Internet is assigned a unique 32-bit address, called an IP address, also known as an internetwork address. The IP address consists of 4 digits, each with a value of 0~255, with a point number between the numbers. Separate, for example: 210.38.32.4 in fact, each IP address is made up of both the network number and the host number. The network number indicates the network to which the host is connected, and the host number identifies the particular host on the network. For example, the 210.38.32 is the network number, and 4 is the host number.

What is a domain name?

IP address is a number to represent the address of the host, more difficult to remember. In order to use and remember conveniently, and to facilitate the hierarchical management and distribution of network addresses, the Internet adopted a domain name management system in 1984, with each host having a domain name similar to the following:

Host number. Name of the institution. Network name. top-level domain name

The domain name is expressed in a short set of English, which is easier to remember than the IP address with the digital expression. For example: Beijing Telegraph Office of an Internet-connected computer host IP address is 202.96.0.97, the domain name is PUBLIC.BTA.NET.CN, the meaning is: The host number is public. Beijing Telegraph Office. The Network Center. Net.cn expressed as a post and telecommunications network, the domain names of the other nets in China are:. AC. CN for scientific research network. EDU. CN for the BoE network. CN is represented as the Golden Bridge network.

All levels of Internet network are named and assigned to the host in the network according to the naming rules of the domain name management system, and are responsible for the conversion of domain name to IP address when the communication is completed. For the user, we will most of the situation can not use the IP address, and the direct use of domain names, the Internet's service system automatically converted to IP-type address.

What is the relationship between chinanet and the Internet?

Chinanet is a Chinese public Internet network based on internet technology which is operated and managed by China's post and telecommunications department, and is the backbone network of China's Internet. By connecting to the international Internet, chinanet becomes part of the Internet internetwork. Through Chinanet flexible access and access points across the country's cities, you can easily access the international Internet and enjoy the rich resources and services available on the Internet.

The chinanet consists of a core layer and an access layer. The core layer mainly provides the domestic high-speed relay channel and the connection access layer, simultaneously is responsible for with the international Internet interconnection, the core layer constitutes chinanet backbone network. The access layer is primarily responsible for providing user ports and various resource servers. CHINANET at the same time with Chinapac, PSTN, Chinaddn, Chinamail Unicom, in order to facilitate access to users. Chinanet offers 6 2M-speed international lines, which are linked to the US sprint, MCI and at&t networks and 2 128K-speed lines, respectively, to Japan and Singapore.

What is home Page?

Home page: Literal translation homepage. But if it's literally "home" it's wrong, specifically, home Page is an organization of information organized using Hypertext Markup Language (descriptive language), and then translated by a corresponding interpreter or browser, including text, images, sounds, animations, and more. Users can treat it as a newspaper, magazine, TV, radio, and so on. The home page is transmitted by placing the original code and the graphics files and sound files associated with the home page on a single server (called www) query. For example, if you want to know the situation of Taiyuan Radio and TV University, you can browse the homepage of Taiyuan Radio and TV University, it should be placed on the WWW server of Taiyuan Radio and TV University, then input in the browser URL input:

What is DNS?

Every time the network connection problem, when asked the engineer, their answer is usually: "The line is broken or DNS server hung up", in the end what is DNS server, why it as a machine we can not play on the internet?

DNS is called domain name server, before the description of DNS server, you may want to explain what is Domain name, the way to identify a computer on the network is the use of IP, but a set of IP numbers is not easy to remember, and there is no association of meaning, so we will be the network On the server to take a meaningful and easy to remember the name, the name we call it "domain name".

For example: Taiyuan Radio and Television University school site, the general user browsing the site, will be input, and very few people will remember the IP server is how much? So is the Taiyuan Rtvu's domain

Name, and 210.38.32.4 is its IP, just as we call a friend, it must be called his name, almost no one is called each other ID card size!

But due to the fact that the Internet is a real identification of the machine or IP, so, when the user enters domain name, the browser must first go to a host with domain name and IP corresponding data to query the IP of this computer, and this is the host that is checked, we call it domain N Ame Server, referred to as DNS, for example: When you enter, the browser will send this name to the nearest DNS Server to do the identification, if the inquiry is found, it will return the host IP, and then ask for information, but if not found, it will occur similar to DNS not FOUND situation , so once DNS server becomes a machine, it's like the road signs are completely destroyed and no one knows where to send the data.

Unlike our average person's name, domain name and IP, each domain name must correspond to a set of IP, but is unique, and IP is the same, domain name can not be repeated.